From PGSC Wiki
Jump to: navigation, search

Questions in this category have been asked by

  • How can you tell the mass and age of a globular cluster?
  • What is the typical M/L ratio for a GC? Explain why (age, luminosity dependence on mass).
  • Draw an HR diagram for a globular cluster
  • What is pleides? What is its mass?
  • Tell me about globular clusters in a Galaxy. (SR) (Variation, (PJ): What is a globular cluster?)
    • Mass, Number of Stars, Spatial Distribution in a galaxy, Typical Ages, Number in the Milky Way and in M87...
  • What is the Spitzer instability? (SR)
  • How many globular clusters are there in the galaxy?
  • How far are they typically from Sag A*?
  • How does the average mass of a globular cluster in stars compare to the MW disk?
  • How can one determine the mass of of a globular cluster from its velocity dispersion?
  • How does one infer velocities perpendicular to the line of sight in order to measure the velocity dispersion?

Galaxy clusters:

  • What are typical temperatures of the gas in a galaxy cluster?
    • How do we know this?/What is the emission mechanism?
    • What if the gas were instead approximately 10 to 100 K cooler. What would the main emission mechanism be then?